This invention relates to electromagnetic waveguides and particularly to waveguide load structures.
In waveguide signal transmission systems there is sometimes a need to provide amplitude equalization for different components of the signal. Existing forms of waveguide equalizers are somewhat inflexible and not entirely satisfactory in providing the desired performance. One known form of waveguide equalizer involves a stepped waveguide load having the steps dimensioned to cause signal attenuation at a selected frequency. This form of load is not tunable once it is constructed. Also, the slope of the match is not adjustable and additional inflection points cannot be added. Thus, the correction of multiple ripples in the system response cannot be done with a single stepped waveguide load.
As indicated by the foregoing, there is a need for a waveguide load structure that provides a multipole frequency response for compensating for multiple ripples in the system response pattern. It would also be desirable to have a waveguide load structure which is tunable to adjust the shape and slope of its response curve to match a desired frequency profile.
In accordance with one feature of the invention, there is provided a new and improved resonant waveguide load structure for use in waveguide signal transmission systems. Such load structure includes a length of waveguide that is open at one end and closed at the other end. Such load structure further includes a resonant body suspended in the waveguide near the closed end thereof.
In accordance with another feature of the invention, there is provided a resonant waveguide load structure which includes a length of waveguide which is open at one end and closed at the other end. A support pin is mounted inside the waveguide near the closed end thereof. A resonant body is mounted on the support pin. At least one spacer member is mounted on the support pin for maintaining the position of the resonant body on the support pin.
In accordance with a further feature of the invention, there is provided a new and improved waveguide equalizer apparatus. Such apparatus includes a waveguide circulator having at least three ports, one of which is an input port and another of which is an output port. The apparatus also includes a waveguide load structure having one end coupled to a third port of the circulator located intermediate the input and output ports. This waveguide load structure is closed at the end opposite the circulator-coupled end. The apparatus further includes a resonant body suspended inside the waveguide load structure near the closed end thereof.
For a better understanding of the present invention, together with other and further advantages and features thereof, reference is made to the following description taken in connection with the accompanying drawings, the scope of the invention being pointed out in the appended claims.